WORCESTER — A Worcester man arrested Friday in Auburn on a drunken-driving charge is scheduled to undergo an evaluation later this month to determine whether he is mentally competent to stand trial.

David Silvestri, 60, of 20 Shelby St. was arrested early Friday morning in Auburn for what a judge later determined to be his fifth alleged offense of driving under the influence of alcohol. While Auburn police said Mr. Silvestri had at least eight, and possibly as many as 10, prior drunken-driving convictions dating back to 1974, Judge Andrew M. D'Angelo said he was only able to determine with certainty from his reading of Mr. Silvestri's criminal record that he had four previous convictions.

Prosecutors filed a petition asking that Mr. Silvestri be deemed a danger to the public and that he be held without bail for up to 90 days while awaiting trial. A dangerousness hearing that was to have been held Tuesday in Central District Court was postponed after Mr. Silvestri's lawyer, Nathan M. Wong, asked that his client first undergo a preliminary competency evaluation.

Maria Masotta, a court-designated psychologist who was to conduct the evaluation, later told Judge Paul L. McGill she was unable to render an opinion on Mr. Silvestri's competency to stand trial because he was in need of medical intervention and possible detoxification.